Indonesia was possibly unaware Australian Navy vessels made repeated incursions into their waters, until it was told by Australia.
Evidence provided during a Senate committee inquiry into the incidents suggests Indonesian authorities could have remained ignorant to the breaches between December 2013 and January 2014 under the federal government’s Operation Sovereign Borders.
“They certainly didn’t raise it with us or draw it to our attention,” head of Customs and Border Protection Michael Pezzullo told the committee on Friday.
“Whether they were aware or not through their own systems I just don’t know.”
Incursions were reported to senior Australian officials on January 15, who passed information on to the Indonesian government the next day.
Indonesia responded by stepping up its naval presence monitoring its southern border.
Australia has since confirmed there were six incursions, some of which may have occurred during the tow-back of asylum seeker boats.
Border protection authorities are assessing whether lapses in judgment contributed to the incidents, which have been described by academics as breaches of international law.
Operation Sovereign Borders commander Angus Campbell believes they were inadvertent.
“Knowing the culture and professionalism of both the Navy and the Customs and Border Protection Service it is quite frankly personally inconceivable that anyone would have wilfully done so,” he told the committee.
Mr Pezzullo can recollect no other instance of Australian government vessels crossing into a neighbours’ territorial waters and refuted suggestions it was deliberate.
“It’s inconceivable to me that in six occurrences … insubordinate defiance by intentionally going into territorial waters contrary to stipulation would have occurred,” he said.
Customs and Defence carried out a joint review of the incursions which made five recommendations to prevent further breaches.
Inquiries are underway in relation to the professional conduct of relevant personnel, while training regimes are under review.
Lieutenant-General Campbell is confident such incursions will not be repeated.
“The thoroughness of the review, its broad recommendations and the more immediate active control measures that were put in place will ensure that it doesn’t happen again.”
Mr Pezzullo said it is government policy to prevent asylum seeker boats illegally entering Australia’s territorial and contiguous waters.
As part of its operation the government has spent $2.5 million on life boats to send asylum seekers back to Indonesia.
The orange craft have been pictured washed-up on shore in Indonesia and the committee was told there will be no attempts to retrieve them.
“They are treated as consumable items once they are used … (they) do not need to be returned or sought,” Mr Pezzullo said.